Multi-Trigger3 AstroSplash Digital Display

The Multi-Trigger 3 and AstroSplash from HiViz.com are very nicely thought out kits.

Using good quality components and nicely detailed build instructions.

However, the one problem I found, was that after use & packing away, it was very difficult to set up again to the exact previously used settings, wasting much time having to take many test photos.

To this end, I built a simple little device, which catches and records the delay timing from the Multi-Trigger 3, and optionally the AstroSplash drop time & delay settings, displaying them on a small LCD in digital format.

The settings can simply be noted for future reference.

Just a few cheap items are required.

Arduino Nano. This is a cheap microprocessor, pre-mounted on a pcb complete with power supply, USB interface & connection pins.

LCD module. LCD, pre-mounted onto a pcb, complete with interface board & connection pins.

Wires. Dupont wires are pre-made wires, to mate with the pins on the two boards above. This makes assembly very easy.

4 resisters. Used as a 'potential Divider' to interface the HiViZ unit to the Digital Display

Length of 2 core cable. To connect power & test ports from HiViz units to the Digital Display.

Veroboard. Used to mount the Arduino Nano and resisters

Stand. Optionally, a clear plastic stand can be purchased, to mount the LCD and Nano into, In turn this can be mounted to the Trigger-Timer 2 or AstroSplash, or left free-standing.

PDF document has full details & photos, with links to suppliers

Building the device is very simple.

Four wires connect from the Arduino to the LCD.

Two power connections are needed (+V and 0V) to connect to the HiViz box

A cable to the HiViz unit test socket (or pulse on 3+).

If the digital display is mounted permanently to the HiViz unit, these connections can be directly soldered to the HiViz unit.

For connection to the second HiViz unit, a flying lead and BNC connector can be used.

Three schematics detail the wiring.

Connection to Trigger-Timer 3 and optionally AstroSplash

Connection to AstroSplash only.

If a common power supply to both Trigger-Timer 3 and Astrosplash is used, an optional way of wiring,

Firmware is loaded from the PC to the Arduino Nano using a program called AVRDUDESS.

Full details of how to do this are detailed in the PDF document.

The firmware itself, is also below, called MultiTrigger3_Astrosplash_LCD_1_9_0.ino.hex.

Note any firmware updates will be posted on Github (I will try to post here as well, but may forget).

Link is in the PDF.

I would really be grateful if you start to build the Digital Display, that you go to the Photrio thread and say hi. Also please post photos of your completed unit.

Please refer to Photrio for further build help & to let us know you are building the digital Display.

Build a B&W film developing timer & twiddler - Cheap, Easy & it Works | Photrio.com Photography Forums

(There is no separate thread for the Trigger-Timer digital Display)

GitHub repository where all documentation & code can be found. billbill100 (github.com)

Multi-Trigger 3 Digital User Guide         28/02 2024

The use of the Trigger-Timer Digital Display is quite straight forward.

The Arduino Nano should have already been connected to the MultiTrigger3 and/or Astro-Splash.

On turning on, the LCD will ask for the Astro-Splash to be triggered. If no input is detected, it is assumed there is no Astro-Splash and the display will simply show the Multi-Trigger delay time between trigger & flash firing, after each trigger event.

If an Astro-Splash is detected, then the display will have the same layout as the Astro-Splash

On the top row, each of the ‘TIME ON’ readings will be shown

and below this, the two ‘TIME OFF’ results and the final value shows the Multi-Trigger delay time.

Each time the Multi-Trigger/Astro-Splash is triggered, the display will automatically update.

The LCD will display the results as below:-

TIME ON            TIME ON            TIME ON

TIME OFF          TIME OFF          Multi-Trigger delay.

Change Log

V 1.0

In my build, I mounted the Arduino Nano on a piece of vero-board, which then slots into the groves in the box.

The Dupont wires will still fit onto the Arduino Nano pins, but with reduced length, so hot-glue was used to secure them.

The four resisters were also added to the vero board. As I use a single power supply and a Y lead for both HiViz units, the 0V wires going to the test connector are not needed and in the final photo, the Y power lead can be seen and just one wire going to the centre of the BNC connector

The acrylic LCD holder can be seen (rear view) hot-glued to the Trigger-Timer 3

When I built the Digital Display, it worked very well.

It is now packed away & I have no access to it, so the schematics and much of the documentation here have been written from memory.

The test port output voltage from HiViz is around 8 volts (according to HiViz, I have never actually measured it)

This in theory means it is too high to directly connect to the Arduino input pins.

For this reason, the inputs are shown with two resisters, forming a 'potential divider' which halves the voltage.

The Trigger-Timer 3 power switch, disconnects the 0V supply and AstroSplash conversely disconnects +V. If, like me you power both Multi-Trigger and AstroSplash from the same power supply, using a Y lead, you will find the Digital Display does not turn off when the Trigger-Timer power switch is turned off.